json 可以只有键没有值吗?

Can json have only key without value?

Json 格式定义键和值。还有下面的

{
      "Kill"
}

它是可接受的 json 格式吗?

不是,在JSON notation中,对象是key/value对的无序集合,key和value都是必须的元素

如果您显示的对象只是 您想要在 JSON 文本中包含的东西,您可以删除对象包装器:

"Kill"

完全正确 JSON。 (曾经有一段时间 JSON 被定义为要求最外层的元素是对象或数组,但很多很多年都不是这样了。)

original JSON introduction 非常straight-forward,包括可能的构造图。其中正文内容是这样的:

An object is an unordered set of name/value pairs. An object begins with { left brace and ends with } right brace. Each name is followed by : colon and the name/value pairs are separated by , comma.

后面的ECMA-404 standard包括类似的措辞:

An object structure is represented as a pair of curly bracket tokens surrounding zero or more name/value pairs. A name is a string. A single colon token follows each name, separating the name from the value. A single comma token separates a value from a following name.

IETF standard, RFC 8259是这样说的:

An object structure is represented as a pair of curly brackets surrounding zero or more name/value pairs (or members). A name is a string. A single colon comes after each name, separating the name from the value. A single comma separates a value from a following name. The names within an object SHOULD be unique.

在每种情况下,请注意 每个 键后跟一个冒号和一个值。由于您的示例中的键后面没有冒号,因此它无效 JSON.